Improved arithmometer



T. HILL. A'RITHMOMETER.

No. 18,692. I Patent ed Nov. 24, 1857.

UN TED STAT S- PATENT THOMAS HILL, OF WALTH AM, MASSACHUSETTS.

IMPROVED ARlTHMOMETER.

Specification forming part of Letters Patent No. 18,62, dated November 24, 1857.

To all whom it may'concern:

Be it known that I, THOMAS HILL, of Waltham, in the county of Middlesex and State of Massachusetts, have invented a new and useful Mechanical Calculator for the Purpose of Performing Various Mathematical Calculations, of. which the followingis afull, clear, and exact description, reference being had to the accompanying drawing, making part of this specification, in which the figure is a perspective view of my machine,part of the case being removed to show the mechanism within. I will first explain the mechanical construe tion of the calculator, andthen describe its operation. V

In the drawing, A is. the case or frame of the machine, in suitable bearings iu'the'sides of which is hung the shaft B, which carries the count-wheels O and D, of which there may be any required number, the wheel C representing units and the wheel D tens, and so on. These wheels are constructed and arranged in the following manner: Each wheel has marked on its periphery at equal distances apart in the row the figures 1 2 3 t 5 6 '7 8 9 0-, repeated as often as the size of the wheel and the distance of the figures will allow. Alongside this first rowis placed asecond one of the same series of figures, but with their position reversed with regard to the first ones, so that figure 9 of one row comes opposite O of the other. That they maybe more, read- .ily distinguished, the figures of one row are made larger than those of the other-I The larger figures are used foraddition and multiplication, the smaller ones for subtraction and division. Each wheel has attached to its side a ratchet a, which is operated by 'a feedpawl 12, attached to the end of a lever E, placed opposite to the face of the wheel and at right angles to the axle B. The pawl b is pivoted to the end of the lever at c,andis held in contact with the ratchetbyaspring d. The other end of the lever E is pivoted to the frame at e, and is held up in position bya spring fbeneath it. Through the top or lid of the case over each lever E project the pins or keys 2', which are arranged in a row along the lever They are numbered from 1 to 0, (in the drawing but six are shown) and as they are nearly of uniform length their position over the lever or the place on its length on which each pin strikes will regulate the amount of .the depression of the outer end of the lever to which the pawl b is attached-*that is, when the key marked 1 is depressed the lever E will be vibrated sufiiciently far for the pawl d to feed forward the wheel to which this lever belongs one notch or number. (The num-, ber of notches correspond with the number of figures on the wheel.) lVhen-the key 6 is depressed, it being nearer the point at which the lever is pivoted will vibrate it a greater" distance, and the pawlb will feed forward the wheel the distance of six numbers.

There is a lever Eand a rowof keys 1' for each count-wheel used. The count-wheels are arranged with a double row of figures in the manner described to save employing a greater number of Wheels, as the same wheel serves both' for addition and subtraction by using the difierent rows of figures.

A card is attached to the front of the case A through. suitable holes g, in which the numbers on the wheels may be read. l

A pin it is secured to one side of the case. Around this is wound a spring, which holds a retaining-pawl k in contact with the ratchet of the wheel ,0. A similar pawl Z drops into the notches of the ratcheta of the wheel D. This pawl serves also. to feed forward the wheel D at intervals, as will be more fully explained. A-light shaft m, supported in the sides of the case, carries a sleeve F,.which turns freely upon it. To vthis sleeve is at ta'ched an :arm G, to the outer end of which is pivoted the pawl Z, and an arm H, which is vibrated at intervals by the revolution of the wheel 0 in the following mannerz-On the side of the wheel 0,.alongsideof its ratchet a, is attached a wheel-I, having teeth n at such intervals that when the wheel 0 has revolved a distance equal'to the space occupied by ten figures on its rim one of the teeth it shall strike the arm H and vibrate it and the arm 'G, which movement thrustsfore ward the pawl Z and moves the wheel- D one notch. When more wheels are employed, this arrangement will be continued on, so that thewheel D moving the space of ten figures shall operate the succeeding wheel one notch, and

so on. A spiral spring p is fastened to the case and to the pawl I. It serves to hold thepawl in contact with the ratchet, and also to draw back the arm G when the arm ll escapes from the tooth 72.

Operation: The larger characters are to be used for addition and multiplication and the smaller ones for subtraction and division.

The process of addition is as follows: The wheels being each arranged with the character 0 opposite the openin s g, thekey i, which corresponds to the first figure of the column to he added, is depressed, then that one cor- ,"responding to the next figure, and so on through the column, using the first row of keys or those belongingto wheel (i'when adding a single column or one in the units place. Each time a key is depressed the wheel (I will be fed forward, in the manner before explained, a distance corresponding to thenumber of the key depressed, and each time ten is counted on this wheel a tooth or on the wheel I will vibrate the arms H and G, and the wheel 1) will be fed forward one number, counting ten, and by a similar arrangement when this wheel has moved a space of ten ures it will operate the succeeding wheel of the series and count one on it or one hundred. (Only two wheels are shown on the drawing;

placed in position to read the greateramount elf through the openings g in the card. The figures composing the smaller amount or that to be subtracted are noted or struck upon the keys, as in the previous operation, when the result can be read off from the wheels.

For multiplication the circle of larger figures is used, starting at 0. The keys corresponding to the figures in the multiplicand are depressed as many times as will make up the sum of the multiplier. Thus it five is to i be multiplied by three the key 5 is depressed three times, when the sum will show through the card-viz., 1 on the wheel .D and 5 on the wheel C-and in the same mannerifor higher numbers where more wheels are used.

For division use the smaller figures. Arrange the wheels so that the dividend willbe opposite the openings in the card, then depress the kcy or keys corresponding to the divisor as many times as is requisite to bring up a number less than the divisor. This numher will be the remainder, and the numberof times the key has been depressed ill be the quotient. Thus if eight is divided by three the small figure S is brought opposite the opening 9 and the key 3 is depressed, when the figure 5 will appear. As this is greater than three, the key must be again depressed, when 2 will appear. This is the remainder, and as the key has been depressed twice two will be the quotient.

With the above-described machine the operator can by mere mechanical operation of pressing the keys corresponding to the figures employed perform the most laborious computations with dispatch and certainty.

\Vhat I claim as-niy invention, and desire to secure byLetters lateut, is-

. THOMAS HILL.

Witnesses;

R. Mortals COPELAND, ANNE F. HILL.

l. The use in a mechanical calculator of i 

